Could it finally be? Could this be the last time we say, coming up, the fight of the century? Tomorrow night in Las Vegas, Floyd Mayweather, Jr. and Manny Pacquiao really are finally fighting. And joining me now from Las Vegas to talk about this ballyhooed boxing match is NPR sports correspondent Tom Goldman. Hi, Tom.

TOM GOLDMAN, BYLINE: Hi, Robert.

SIEGEL: And first, where in Vegas are you?

GOLDMAN: You know, sadly I'm not in one of those neat little castle turrets on the Excalibur Hotel, Robert. I just couldn't pull that off. But I am close. I'm on the strip. I'm across the street from the MGM Grand, where this so-called fight of the century will happen, barring any unforeseen delays. And, remember, this is boxing, so anything could happen. In fact, Manny Pacquiao's trainer, Freddie Roach, said this week Mayweather may not even show up for the fight, which, of course, is probably Freddie Roach just being Freddie Roach. Mayweather will show up, so will Pacquiao. The anticipation and betting is building to a fever pitch here. According to pregame.com, the fight's expected to generate more than double the betting action of any a boxing match ever. Some estimates say $70 million in Nevada alone - none of that mine, Robert.

SIEGEL: Well, Tom, yeah, talks to us from your high-roller suite there in Vegas. This is the fight for the welterweight championship. Welterweight is about the 145-pound range. When the bell sounds, what do you expect to happen?

GOLDMAN: Well, obviously that's a guess. We can look at their bodies of work and try to predict. Manny Pacquiao traditionally is the attacker - very quick - a quick and powerful puncher. He throws a lot of punches rapid-fire. And he often gets an advantage because he's left-handed and the punches are coming from different angles than most opponents are used to. And his quickness could be a key - the way he darts into different punching positions, the way he can close on the opponent who's backing away and thinking he's safe by backing away.

That's a tactic Floyd Mayweather favors. He's traditionally a defensive fighter. He lets the action come to him, then he counters punches very effectively. He's one of the great defenders ever in the ring. So this is pretty basic - not too difficult for viewers to figure out. It's a great attacker against a great defender. They're both little guys. Mayweather's 5'8". Pacquiao's a little over 5'6". But they are and will be ferocious in the ring.

SIEGEL: A lot people say this fight is five years overdue. How might that delay and the ages of these men affect tomorrow's fight and tomorrow's fighters?

GOLDMAN: You know, there's the potential impact physically, obviously. Mayweather's 38. Pacquiao's 36. They're both supremely conditioned, but if this fight goes the distance - 12 rounds - we may see some slowing we might not have seen five years ago. Then there's also the psychological factor to their advanced boxing ages. They've evolved as people. Pacquiao has become very religious and there have been questions in recent years about whether he's lost the killer instinct in the ring.

Mayweather reportedly said in the last year he was tired of boxing and was looking forward to retirement. But both men say they're ready for this one. They've both been very businesslike in lead-up. Those who were desperate for hype have been disappointed because, you know, there really haven't been the wild theatrics that often come before big boxing matches. Both these guys are pretty dialed in.

SIEGEL: And who's expected to win?

GOLDMAN: Well, Mayweather's favored, and a lot of boxing experts and actual boxers think he'll win. One of them, Oscar De La Hoya, who fought both and lost to both, he said an interesting thing. He said, well, the popular notion is that the fight won't be as good as it would have been five years ago. He thinks it may even be better because both men have lost some foot speed. They won't be as quick around the ring, and it will mean more punching and punches landed - more exciting that way. De La Hoya, by the way, picks Mayweather.

SIEGEL: And does boxing win with this fight?

GOLDMAN: That's an interesting question. Tomorrow night, yes, assuming it's a good fight. Obviously there's been tons of publicity, huge amounts of money generated. But beyond tomorrow, as long as there's no rematch, probably not a long term victory for the sport. Boxing will never regain the luster it had decades ago. Remember, after Mayweather and Pacquiao are gone - and they may be gone as soon as tomorrow night - there's no one - no one, two or three dynamic fights to fill their void.

SIEGEL: Thank you, Tom.

GOLDMAN: You're welcome, Robert.

SIEGEL: That that's NPR's sports correspondent Tom Goldman speaking with us from the Strip in Las Vegas. Transcript provided by NPR, Copyright NPR.